Cod sursa(job #626781)

Utilizator ContraPunctContrapunct ContraPunct Data 28 octombrie 2011 11:49:42
Problema Range minimum query Scor 40
Compilator cpp Status done
Runda Arhiva educationala Marime 0.94 kb
#include <stdio.h>
#define NMAX 100002
using namespace std;

long int rmq[20][NMAX];
long int n,m;
long int lg[NMAX];
long int a[NMAX];
long int min(long int a, long int b)
{
	if(a<b)
		return a;
	return b;
}

void ReadData()
{
	long int i;

	scanf("%ld %ld",&n,&m);

	for (i=1;i<=n;i++)
		scanf("%ld ",&a[i]);
}
void Init()
{
	long int i;
	lg[1]=0;
	for (i=2;i<=n;i++)
		lg[i]=lg[i/2]+1;

	for (i=1;i<=n;i++)
		rmq[0][i]=a[i];
}
void RMQ()
{
	long int i,j,l;
	for (i=1; (1 << i) <=n;i++)
		for (j=1;j <= n - (1 << i)+1;j++)
		{
		l=1<<(i-1);
		rmq[i][j]= min( rmq[i-1][j] , rmq[i-1][j+l] );
		}
}
void WriteData()
{
	long int x,y,diff,sh,i,l;
	
	for (i=1;i<=m;i++)
	{
		scanf("%ld %ld",&x,&y);
		
		diff=y-x+1;
		l=lg[diff];
		sh=diff - (1<<l);
		printf("%ld\n",min(rmq[l][x],rmq[l][x+sh]) );
	}	
}
	
int main()
{
	freopen("rmq.in","r",stdin);
	freopen("rmq.out","w",stdout);

	ReadData();
	Init();
	RMQ();
	WriteData();
	
	return 0;
}